An NSC maturity value is a one-line formula. What trips people up is the tax: the interest is taxed every year even though you receive nothing until year five, and for the first four years the same interest can be claimed again under 80C. Most sheets skip that part. This one lays out the interest year by year, marks which years count for 80C, and shows the tax in both situations.
Download: NSC calculator (.xlsx, free)What the sheet does
- Works out the maturity value and the interest for each of the five years.
- Marks the interest from years one to four as claimable again under 80C, and totals it.
- Shows the tax on the interest two ways: when you have 80C room every year, and when your 80C is already full or you are in the new regime.
- A plain .xlsx with no macros, for Excel, Google Sheets and LibreOffice, licensed CC BY 4.0.
The rules the sheet uses
- Interest rate: 7.7% a year for October to December 2026, compounded yearly and locked for all five years on the day you buy.
- Amount: ₹1,000 minimum, in multiples of ₹100, with no upper limit.
- The amount you invest counts under 80C in the year you buy, in the old regime, within the ₹1.5 lakh limit you share with PF, PPF, ELSS and the rest.
- The interest is taxable every year. For years one to four it is treated as reinvested, so the same amount can be claimed under 80C again. Year-five interest is only taxed.
Source: Small savings interest rates for Oct–Dec 2026 (Ministry of Finance, 30 Sep 2026), as reported
₹1 lakh at 7.7%, worked through
- Interest by year: ₹7,700, ₹8,293, ₹8,931, ₹9,619 and ₹10,360. Maturity value: ₹1,44,903.
- Interest claimable again under 80C, years one to four: ₹34,544.
- In the 30% slab with 80C room every year, the tax that sticks is on year-five interest only: about ₹3,232 including cess.
- If your 80C is already full, or you are in the new regime, all ₹44,903 of interest is taxed: about ₹14,010 in the 30% slab.
That gap, about ₹10,800 on a ₹1 lakh certificate, is the whole case for NSC in the old regime. Without spare 80C room, it is a taxable 7.7% deposit and should be compared with one.
What the sheet does not do
- It does not know the rest of your 80C. Check that PF, PPF, ELSS, insurance and tuition fees leave room before counting on the reinvested interest.
- It applies one slab to all five years. If your income will change, adjust the slab cell.
- Joint certificates and transfers are outside its scope.
Frequently asked questions
- What is the maturity value of ₹1 lakh in NSC?
- At 7.7% compounded yearly for five years, about ₹1,44,903, so about ₹44,903 of interest.
- Is NSC interest taxable every year?
- Yes. It is added to your income each year. For the first four years the same interest is treated as reinvested and can be claimed under 80C again in the old regime; year-five interest is only taxed.
- Does NSC save tax in the new regime?
- No. The new regime has no 80C deduction, so neither the investment nor the reinvested interest is deductible there.
- Does the sheet work in Google Sheets?
- Yes. Upload the .xlsx to Google Drive and open it with Google Sheets; the formulas carry over.